A connector for a flat belt comprises at least one pair of U-section end clips interconnected by a transverse coupling pin or rod. Each such clip typically is made of metal and has a pair of legs adapted to embrace the respective belt end and a bight portion interconnecting the outer ends of the legs. Each leg in turn is formed with at least two throughgoing holes that align with the holes of the leg on the opposite face of the belt, and staples are driven through the registering holes from one side of the belt and are crimped over on the other side. The bight portion is formed as at least one loop or knuckle and the loops of the clip or clips of one belt end are interleaved with those of the other belt end and the coupling pin passes through the resultant passage to couple the two belt ends together.
As a result of tensile, bending and frictional forces acting on the curved bight portions and the coupling rod, the bight portions and the rod are subjected to extremely heavy wear. The wear results eventually in damage to the rod and bight portions and consequently to the entire conveyor-belt connector. A further result of this damage is expensive repair work and breaks in operation.
For this reason, coupling rods have been developed containing a bunched steel wire core and a helically wound steel jacket. Other embodiments do without the steel jacket and consist of twisted bunches of steel wire. Attempts have even been made to use bunches of glass and carbon fibers, but have not proven effective. The bight portions of belt-connector clips are regularly doubled, either by displacement of ductile material or by crimping over. This procedure, however, does not eliminate wear, and at best delays the damage resulting from wear.
Further a coupling pin for belt connectors for inter-connecting the ends of conveyor belts is known from German 4,416,079 of W. Herold wherein core elements of a defined length are disposed inside at least one outer element. In this known coupling pin the outer element is in the form of a relatively soft material which distorts in use while the core elements each have a length sufficient to extend through more than two hinge loops of the connectors. The outer element serves only to produce the pin-like structure and for the introduction of the inner elements into the hinge loop zone of the connectors.
However, the outer element cannot withstand the stresses occurring because it is made of a relatively soft material which deforms in operation. Instead, the stresses are intended to be transmitted solely by the core elements. This cannot happen, however, simply because the considerable wear between the hinge knuckles and the coupling pin is bound to lead to early damage and finally destruction of the soft outer element. This leads to loosening of the inner core elements.